1. Field of the Invention
The present invention relates to an image forming method, a pretreatment liquid used in such method, and a cartridge housing such pretreatment liquid set therein.
2. Description of the Related Art
It has been proposed in the conventional art that a first liquid and a second liquid are mixed on a recording medium to induce aggregations of a polyvalent metal salt and a pigment, and a crosslink reaction between adipic acid dihydrazide and polyvinyl alcohol or a water-soluble polymer at the same time to thereby improve fixation of an ink (see International Patent Application Publication No. WO 04/026976, and Japanese Patent (JP-B) No. 4136814).
Between the aggregation reaction and the crosslink reaction, speed of the aggregation reaction is a lot faster then the crosslink reaction, and thus this proposal is not effective for attaining abrasion resistance just after printing.
The present inventors have proposed an image forming method in which as a pretreatment liquid, acid and an oxazoline group-containing polymer are applied to a recording medium before ejecting an aqueous recording ink onto the recording medium (see Japanese Patent Application Laid-Open (JP-A) No. 2010-131779). The technique of this proposal achieved improvements in both image density and fixing ability. However, this proposed technique clearly improved the fixing ability compared to the case where only acid was applied, but the fixing ability was poor compared to the case where the pretreatment liquid was not applied at all.
Accordingly, it is a current situation that there is a strong demand for an image forming method which realizes both high image quality and fixing ability in high speed printing by a liquid ejecting device, as well as a pretreatment liquid set used in such method, and a cartridge housing such pretreatment liquid.